The present invention relates generally to an electrical junction box. In particular, the present invention relates to an electrical junction box which is adapted for use with cylindrical structures such as concrete piers used as mounting platforms for light poles or other similar structures. The electrical junction box according to the present invention provides protection and convenient access to electrical wires and other devices embedded within the cylindrical structure.
Electrical junction boxes are generally used in structures such as buildings to provide access to electrical power to electrical devices such as lighting fixtures or electrical receptacles. Typically, electrical power wires are routed into junction boxes. Inside the junction box, wires for supplying power to the electrical device are connected to the electrical power wires. Thus, the junction box provides a convenient location for the connection of an electrical device to electrical power lines.
In outdoor environments when electrical power is needed, for example, to supply power to a parking lot light, typically, the electrical power wires are routed directly to the electrical device without the use of a junction box. There are many disadvantages to this method of wiring. First, construction and installation are more difficult. For example, when installing a light pole, generally electrical power wires are routed underground through conduit to the location where the light pole is to be installed. A hole is dug at the location where the light pole is to be installed. A form such as a Sonotube.TM. form is installed in the hole and conduit is placed in the form. Concrete is poured in the form which provides a mold for the formation of a concrete pier on which a light pole will be mounted. After the concrete has cured and set, the power wires must then be pulled out of the conduit in the ground, pulled through the conduit in the concrete pier, and connected to the light fixture on the light pole. This method of installation is disadvantaged because, among other things, of the difficulties in constructing a concrete pier and at the same time providing access to the electrical power wires in the ground. Special care must be taken to insure that the electrical power wires are accessible after the concrete pier has cured. It is also difficult to pull the electrical power wires out of the ground, through the concrete pier, into the light pole, and up the light pole to the light fixture at the top of the light pole. Also, if additional electrical devices are required after the light pole has been wired, there are no convenient locations for connecting additional devices to the electrical power wires.
One attempt at simplifying the wiring of light poles is the metallic circular wedged shaped junction box disclosed in U.S. Pat. No. 5,553,730. The junction box disclosed therein is specifically designed to be cast within a cylindrical concrete pier. The junction box has curved front wall and front edge portions that have a radius of curvature substantially equal to that of the exterior of the concrete pier into which the junction box will be positioned. Thus, when the junction box is installed it substantially fits within the concrete pier and mounts substantially flush with the curved cylindrical concrete pier. This junction box simplifies the wiring of light poles because it provides a convenient location for connecting wires from the light pole to the electrical power wires.
During construction of the concrete pier using the junction box disclosed in U.S. Pat. No. 5,553,730, the junction box is positioned into cutouts in the form and the electrical power wires are pulled through the conduit in the form into the junction box prior to the pouring of concrete. After the concrete has been poured, set and cured and the form removed, the light pole can be installed. Wires from the light fixture on the light pole can be run down the light pole and into the junction box. This junction box, however, has many shortcomings. First, the junction box is difficult to install into a form. Some external means is needed to secure this junction box to the form. Second, the junction box is metallic and susceptible to corrosion. Third, the junction box must be installed in the form without the lid, thereby increasing construction costs. Construction costs are increased because the lid and the box are installed in two separate stages and because someone must keep track of the lid to make sure that it does not become misplaced. Fourth, because the junction box has curved walls, it can only be used in a cylindrical pier of a specified diameter and is not adaptable to cylindrical piers having different diameters. Also, the junction box is not U.L. rated and does not meet N.E.M.A. standards for weatherproof capabilities. In addition, the junction box is not easily modifiable to allow the mounting of electrical receptacles thereto. The junction box must also be grounded somehow. Finally, the junction box does not allow for the mounting of additional support hardware such as fuses, circuit breakers, terminal blocks, etc., inside the box.
Therefore, there remains a need in this art for a non-metallic junction box for use in outdoor environments. There remains a more particular need for a non-metallic junction box that can be installed in a cylindrical pier that is simpler and cheaper to install. It is desirable to have a non-metallic junction box for outdoor use that is U.L. listed and meets N.E.M.A. standards for weatherproofing. There, also, remains a need for a junction box that has the capability to mount electrical receptacles thereon and does not require grounding. There remains a need for a junction box that is less expensive to manufacture. There also is a need for a junction box that can be installed as one unit with the top in place. There remains a need for a junction box that can be used in cylindrical piers of different diameters. Finally, there remains a need for a non-metallic junction box that allows for the mounting of additional support hardware within the junction box.